Mobile body control system, control method, and storage medium

ABSTRACT

Provided is a mobile body control system, a control method, and a storage medium in which a mobile body can move to an appropriate angle and distance in accordance with emotion of a communication target. Provided is a mobile body control system that includes a moving unit that moves; a measuring unit that measures an angle and a distance with a target (2) which is a communication target; an emotion estimating unit that estimates an emotion of the target; and a control unit that controls the moving unit to move a mobile body (1) to an initial position with an appropriate angle and distance with respect to the target in accordance with the estimated emotion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of International PatentApplication No. PCT/JP2016/051617 filed on Jan. 20, 2016, which claimspriority benefit of Japanese Patent Application No. JP 2015-087474 filedin the Japan Patent Office on Apr. 22, 2015. Each of theabove-referenced applications is hereby incorporated herein by referencein its entirety.

TECHNICAL FIELD

The present disclosure relates to a mobile body control system, acontrol method, and a storage medium.

BACKGROUND ART

Recently, robots that verbally or nonverbally communicate with peoplehave been proposed and are likely to increase in the future. Incommunication between people and robots, it is necessary to secureadequate personal space for people to occupy comfortably. Comfortablepersonal space varies for each person, but in human-to-humancommunication, people learn from each other how much distance should bekept and maintain comfort.

With respect to a robot that communicates with a person, for example,Patent Literature 1 below discloses a robot that calculates parametersfor an optimal communication action on the basis of a moving distanceand a facial orientation of a person during communication and securesappropriate personal space that an interaction partner can occupycomfortably or adjusts a frequency of matching a gaze with the partner.

Further, Patent Literature 2 below discloses a robot that adjusts a typeof spoken content, a conversation distance, or a time for which eyecontact is maintained in accordance with sensing familiarity based on aconversation distance with a communication target, a gaze position, afacial expression, and other sensing information.

CITATION LIST Patent Literature

Patent Literature 1: JP 2006-247780A

Patent Literature 2: JP 2011-000681A

DISCLOSURE OF INVENTION Technical Problem

However, with the number of communication robots set to increase in thefuture, a technology that sufficiently takes into consideration thepsychological influences such as stress that robots give to people hasnot been proposed. For example, when robots communicate with people, itis expected to cause people stress due to actions that would not occurbetween people, such as when a robot surprises a person by suddenlyappearing in front of them and approaching them. Even if a robot canunderstand a person's emotion, the robot not performing an appropriateaction with respect to the emotion that would be performed by a humancan be a source of stress.

Although a technology of adjusting a distance with a person to secureappropriate personal space with the person has been proposed in both ofthe above patent literatures, controlling a relative angle with respectto the person is not mentioned. For example, even at the same distance,a robot gives a different psychological influence to a person dependingon whether the robot is in front of, obliquely in front of, beside, orbehind the communication partner.

Thus, the present disclosure proposes a mobile body control system, acontrol method, and a storage medium in which a mobile body can move toan appropriate angle and distance in accordance with emotion of acommunication target.

Solution to Problem

According to the present disclosure, there is provided a mobile bodycontrol system including: a moving unit configured to move; a measuringunit configured to measure an angle and a distance with a target whichis a communication target; an emotion estimating unit configured toestimate an emotion of the target; and a control unit configured tocontrol the moving unit to move a mobile body to an initial positionwith an appropriate angle and distance with respect to the target inaccordance with the estimated emotion.

According to the present disclosure, there is provided a control methodincluding: measuring, by a measuring unit, an angle and a distance witha target which is a communication target; estimating an emotion of thetarget; and controlling a moving unit, by a control unit, to move amobile body to an initial position with an appropriate angle anddistance with respect to the target in accordance with the estimatedemotion.

According to the present disclosure, there is provided a storage mediumhaving a program stored therein, the program causing a computer tofunction as: a moving unit configured to move; a measuring unitconfigured to measure an angle and a distance with a target which is acommunication target; an emotion estimating unit configured to estimatean emotion of the target; and a control unit configured to control themoving unit to move a mobile body to an initial position with anappropriate angle and distance with respect to the target in accordancewith the estimated emotion.

Advantageous Effects of Invention

As described above, according to the present disclosure, a mobile bodycan move to an appropriate angle and distance in accordance with emotionof a communication target.

Note that the effects described above are not necessarily limitative.With or in the place of the above effects, there may be achieved any oneof the effects described in this specification or other effects that maybe grasped from this specification.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view for describing an overview of a mobile body controlsystem according to an embodiment of the present disclosure.

FIG. 2 is a view for describing an interpersonal angle, face-to-face,and side-by-side according to the present embodiment.

FIG. 3 is a block diagram illustrating an example of a configuration ofa mobile body according to a first embodiment.

FIG. 4 is a flowchart illustrating a movement control process accordingto the first embodiment.

FIG. 5 is a sequence diagram illustrating another movement controlprocess according to the first embodiment.

FIG. 6 is a view for describing an example of controlling movement ofthe mobile body at the start of communication according to the firstembodiment.

FIG. 7 is a view for describing movement control of the mobile body in acase in which a target person has a positive emotion according to thefirst embodiment.

FIG. 8 is a view for describing movement stop control of the mobile bodyin a case in which the target person is in a normal state according tothe first embodiment.

FIG. 9 is a view for describing another type of movement stop control ofthe mobile body according to the first embodiment.

FIG. 10 is a view for describing movement control of the mobile body ina case in which the target person has a negative emotion according tothe first embodiment.

FIG. 11 is a view for describing movement control of the mobile body ina case in which the target person has a negative emotion according tothe first embodiment.

FIG. 12 is a view for describing vertical movement control of a mobilebody according to modified example of the first embodiment.

FIG. 13 is a view for describing change of an interpersonal angle of themobile body in the case in which the target person has a positiveemotion according to the first embodiment.

FIG. 14 is a view for describing change of an interpersonal angle of themobile body in the case in which the target person has a negativeemotion according to the first embodiment.

FIG. 15 is a block diagram illustrating an example of a configuration ofa mobile body according to a second embodiment.

FIG. 16 is a flowchart illustrating a movement control process accordingto the second embodiment.

FIG. 17 is a sequence diagram illustrating another movement controlprocess according to the second embodiment.

FIG. 18 is a view for describing an example of controlling movement ofthe mobile body at the start of communication according to the secondembodiment.

FIG. 19 is a view for describing an example of controlling movement to aproximate position based on a communication history according to thesecond embodiment.

FIG. 20 is a view for describing an example of controlling movement to aside-by-side position based on a communication history according to thesecond embodiment.

FIG. 21 is a block diagram illustrating an example of a configuration ofa mobile body according to a third embodiment.

FIG. 22 is a flowchart illustrating a movement control process accordingto the third embodiment.

FIG. 23 is a flowchart illustrating an atmosphere estimation processaccording to the third embodiment.

FIG. 24 is a view for describing an example of controlling movement ofthe mobile body in a case in which a surrounding atmosphere is badaccording to the third embodiment.

FIG. 25 is a view for describing an example of controlling movement ofthe mobile body in a case in which a surrounding atmosphere is goodaccording to the third embodiment.

FIG. 26 is a view for describing an example of controlling movement ofthe mobile body in a case in which an atmosphere between a target personand a person close to the target person is extremely good according tothe third embodiment.

FIG. 27 is a graph illustrating an example of the relationship betweenan atmosphere V of a surrounding place and an interpersonal distanced dbetween the mobile body and a target person according to the thirdembodiment.

FIG. 28 is a view illustrating an example of movement control based on acommunication history according to the third embodiment.

FIG. 29 is a view illustrating an example of movement control based on acommunication history according to the third embodiment.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, (a) preferred embodiment(s) of the present disclosure willbe described in detail with reference to the appended drawings. In thisspecification and the appended drawings, structural elements that havesubstantially the same function and structure are denoted with the samereference numerals, and repeated explanation of these structuralelements is omitted.

The description will be given in the following order.

-   1. Overview of mobile body control system according to embodiment of    the present disclosure-   2. Embodiments-   2-1. First embodiment-   2-2. Second embodiment-   2-3. Third embodiment-   3. Summary    «1. Overview of Mobile Body Control System According to Embodiment    of Present Disclosure»

First, an overview of a mobile body control system according to anembodiment of the present disclosure will be described with reference toFIG. 1. As illustrated in FIG. 1, a mobile body control system accordingto the present embodiment is a system that controls motion of a mobilebody 1 realized by a communication robot capable of moving on an x-axisand a z-axis, for example. The mobile body 1 includes various sensorssuch as a camera and a microphone, recognizes a target person 2 on thebasis of a captured image or collected voice, and senses speech or afacial expression of the target person 2. Further, the mobile body 1includes an output device such as a speaker and is capable of verballyor nonverbally communicating with a person by responding with a voiceoutput, a display output, or motion in accordance with a result of thesensing.

Here, when a communication robot communicates with a person, it isexpected to cause stress to the person due to the robot suddenlyappearing in front of the person and approaching the person or enteringthe person's personal space in a state in which the person is notfamiliar with the robot. Also, because personal space varies for eachperson or interpersonal relationship, always keeping the same distanceis not appropriate.

In consideration of the above problem, a mobile body control systemaccording to an embodiment of the present disclosure enables appropriatecommunication by moving to an appropriate angle and distance inaccordance with an emotion of a communication target without causing thetarget person stress.

Specifically, as illustrated in FIG. 1, the mobile body 1 moves to anappropriate interpersonal distance and interpersonal angle with thetarget person 2 in accordance with an emotion of the target person 2,who is a communication target. For example, at the start ofcommunication, the mobile body 1 moves to a position having aninterpersonal angle of about 0 to 20° and an interpersonal distance ofabout 1 m with respect to the target person 2 in a front directionfacing the target person 2. Here, with respect to an interpersonaldistance that takes into consideration the psychological stress given tothe target person 2, the social psychological concept of aninterpersonal distance is used in addition to the biological concept ofpersonal space. The social psychological concept of an interpersonaldistance includes, for example, a close distance (familiarrelationship), an individual distance (a proximate phase: privatecommunication with a close partner, a remote phase: informalcommunication), a social distance (official communication), and thelike, and a person feels stress when an interpersonal distance and aninterpersonal relationship do not match. For example, a person feelsstress when the person is at a close distance or an individual distancewith an unfamiliar person in a crowded train. In the presentspecification, the mobile body 1 is controlled using a remote phase ofan individual distance of about 1 m, a proximate phase of the individualdistance of about 50 cm, and a remote phase of a close distance of about30 cm as examples of definitions according to the social psychologicalconcept of interpersonal distances. Therefore, at the start ofcommunication, the mobile body 1 first moves to a position of about 1 m,which is the remote phase of the individual distance, from the targetperson 2.

The emotion of the target person 2 is estimated on the basis of analysisof a facial expression from a captured image captured by the cameraprovided in the mobile body 1 and analysis of voice collected by themicrophone.

Next, at a time point at which the mobile body 1 is moved to theposition having an interpersonal angle of about 0 to 20° and a distanceof about 1m with respect to the target person 2, in a case in which thetarget person 2 smiles as illustrated in FIG. 1 and can be estimated tohave a positive emotion, the mobile body 1 further approaches the targetperson 2 and moves to a position side-by-side with the target person 2to perform more familiar communication.

Further, when the mobile body 1 is side-by-side with the target person2, the mobile body 1 adjusts an angle to face the same direction as thetarget person 2 to establish a more familiar relationship with thetarget person 2 without causing the target person 2 stress.

Although movement to the interpersonal distance and interpersonal anglefor performing more familiar communication with the target person 2 in acase in which the target person 2 has a positive emotion is illustratedin the example illustrated in FIG. 1, the present embodiment is notlimited thereto. For example, in a case in which the target person 2 hasa negative emotion, the mobile body 1 keeps a long interpersonaldistance with the target person 2 to keep away from the target person 2or increases an interpersonal angle with respect to the target person 2so as not to cause the target person 2 psychological stress.

Here, definitions of “interpersonal angle,” “face-to-face,” and“side-by-side” will be described with reference to FIG. 2. FIG. 2 is aview for describing the interpersonal angle, face-to-face, andside-by-side according to the present embodiment. As illustrated in theupper part of FIG. 2, for example, an interpersonal angle of a target Tawith respect to a target Tb is an angle Ang.a (−180° to 180°) formedbetween a vector from the target Ta to the target Tb and a forwardvector of the target Ta. Similarly, an interpersonal angle of the targetTb with respect to the target Ta is an angle Ang.b (−180° to 180°)formed between a vector from the target Tb to the target Ta and aforward vector of the target Tb. An absolute value of each of Ang.a andAng.b is an angle smaller than a predetermined value, and a case inwhich an absolute value of “Ang.a+Ang.b” is an angle smaller than thepredetermined value is defined as “face-to-face in a broad sense,” whilea case in which an interpersonal distance Xab is further less than apredetermined distance (for example, the remote phase of the individualdistance: about 1 m) is defined as “face-to-face.”

Further, as illustrated in the lower part of FIG. 2, the absolute valuesof Ang.a and Ang.b are both about 90°, and a case in which an absolutevalue of “Ang.a+Ang.b” is an angle smaller than a predetermined value isdefined as “side-by-side in a broad sense,” while a case in which aninterpersonal distance Xab is further less than a predetermined distance(for example, the proximate phase of the individual distance: about 50cm) is defined as “side-by-side.”

The overview of the mobile body control system according to anembodiment of the present disclosure has been described above. The shapeof the mobile body 1 is not limited to the example illustrated in FIG.1, and for example, the mobile body 1 may be a two-foot walking robot, arobot imitating the shape of an animal such as a dog or a cat, or arobot that can fly. Further, the mobile body 1 may be realized as adrone, in addition to a robot. Next, the mobile body control system ofthe present disclosure will be described in detail with reference to aplurality of embodiments.

«2. Embodiments»

<2-1. First Embodiment>

First, a first embodiment according to the present disclosure will bedescribed with reference to FIGS. 3 to 14.

(2-1-1. Configuration)

FIG. 3 is a block diagram illustrating an example of a configuration ofa mobile body 1 a according to the first embodiment. As illustrated inFIG. 3, the mobile body 1 a according to the present embodiment includesa control unit 10-1, a communication unit 11, a distance and anglemeasuring unit 12, a moving unit 13, a camera 14, a microphone 15, aspeaker 16, a position measuring unit 17, and an interpersonal positionknowledge database (DB) 18.

The control unit 10-1 is configured by a microcomputer having a centralprocessing unit (CPU), a read-only memory (ROM), a random access memory(RAM), and a nonvolatile memory and controls each configuration of themobile body 1 a. Further, as illustrated in FIG. 3, the control unit10-1 functions as an emotion estimating unit 10 a, a movement positioncalculating unit 10 b, and a movement control unit 10 c.

The emotion estimating unit 10 a has a function of estimating an emotionof a communication target. Here, the emotion may be a basic emotion suchas “joy” or “sorrow” or may be expressed as two-dimensional coordinatesof valence (inducibility) and arousal (arousal level). Morespecifically, the emotion estimating unit 10 a estimates an emotionusing a mechanical learning method or the like on the basis of a resultof analyzing a facial expression using a facial image of the targetperson 2 captured using the camera 14 or a result of analyzing postureor motion using a body image. The emotion estimating unit 10 a may alsoestimate an emotion using a result of analyzing voice of the targetperson collected using the microphone 15 (for example, spoken content, atone of voice, etc.). The emotion estimating unit 10 a may also estimatean emotion on the basis of an interaction (receding, approaching, or thelike) of the target person 2 with respect to motion of the mobile body 1a. The emotion estimated by the emotion estimating unit 10 a may be abasic emotion such as “joy” or “sorrow” or may be an emotional valueexpressed as the two-dimensional coordinates of valence (inducibility)and arousal (arousal level) as described above. The emotion estimatingunit 10 a may estimate a positive emotion/negative emotion in accordancewith the estimated specific emotion.

The movement position calculating unit 10 b calculates an appropriateposition to which the mobile body 1 moves on the basis of the emotion ofthe target person 2 estimated by the emotion estimating unit 10 a.Specifically, for example, the movement position calculating unit 10 bacquires an appropriate interpersonal distance and angle correspondingto the emotion of the target person 2 from the interpersonal positionknowledge DB 18 and calculates a movement position of the mobile body 1.

Here, parameters (hereinafter referred to as interpersonal positionknowledge data) for calculating an appropriate position (interpersonaldistance and interpersonal angle) to which the mobile body 1 a shouldsubsequently move on the basis of the interpersonal distance andinterpersonal angle between the target person 2 and the mobile body 1 aand the emotion of the target person 2 are stored in the interpersonalposition knowledge DB 18. For example, an initial position, a subsequentmovement position from the initial position in a case in which thetarget person 2 has a positive emotion (emotions such as relief,curiosity, familiarity, and affection), and an interpersonal distanceand an interpersonal angle of a subsequent movement position from theinitial position in a case in which the target person 2 has a negativeemotion (emotions such as tension, fear, and disgust) are stored in theinterpersonal position knowledge DB 18. The initial position may bechanged within a predetermined range in accordance with the emotion(positive/negative) of the target person 2.

The movement control unit 10 c controls the moving unit 13 to move themobile body 1 a to the movement position calculated by the movementposition calculating unit 10 b. Here, the movement control unit 10 ccalculates a moving distance and direction to the movement position withreference to the current interpersonal distance and interpersonal anglemeasured by the distance and angle measuring unit 12 and performsmovement control with respect to the moving unit 13.

The communication unit 11 has a function of transmitting and receivingdata to and from an external device. For example, the communication unit11 may include a first communication unit (so-called connection port)that is connected to another nearby information processing device bywired/wireless connection and a second communication unit that isconnected to a network and connected to another information processingdevice connected via a predetermined server on the network or via thenetwork.

The distance and angle measuring unit 12 has a function of measuring adistance (that is, an interpersonal distance) and an angle (that is, aninterpersonal angle) between the mobile body 1 and the target person 2.For example, the distance and angle measuring unit 12 is realized by astereo camera, a distance measuring sensor using infrared rays, or thelike, and measures the interpersonal distance. Further, for example, thedistance and angle measuring unit 12 finds a facial orientation of thetarget person 2 on the basis of the result of analyzing the facialexpression using the captured image of the face of the target person 2and calculates an interpersonal angle of the mobile body 1 a withrespect to a forward vector (facial orientation or body orientation) ofthe target person 2.

The moving unit 13 has a function of moving the mobile body 1, andspecifically includes a moving mechanism and a power unit. In thepresent embodiment, the moving mechanism and the power unit are notparticularly limited.

The camera 14 is an imaging unit that captures an image of surroundingsof the mobile body 1 and may include a plurality of imaging units.Although an installation position of the camera 14 in the mobile body 1is not particularly limited, the camera 14 may be installed at, forexample, a chest portion, a forehead portion, and a temporal region ofthe mobile body 1.

The microphone 15 is a collecting unit that collects surrounding voiceand outputs the surrounding voice as a voice signal to the control unit10-1 and may be realized using, for example, a microphone array.

The speaker 16 is a voice output unit that converts a predeterminedvoice signal into voice and outputs the voice in accordance with controlof the control unit 10-1. The speaker 16 may be realized using, forexample, a speaker having directivity.

The position measuring unit 17 has a function of measuring the currentposition of the mobile body 1 a on the basis of an acquisition signalfrom the outside. Specifically, for example, the position measuring unit17 is realized using a Global Positioning System (GPS) positioning unit,receives radio waves from a GPS satellite, detects a position of themobile body 1 a, and outputs the detected position information to thecontrol unit 10-1. Further, in addition to the GPS, the positionmeasuring unit 17 may detect the position by, for example,transmission/reception via Wi-Fi (registered trademark), Bluetooth(registered trademark), etc. or short range communication.

The detailed configuration of the mobile body 1 a according to thepresent embodiment has been described above. The configuration of themobile body 1 a according to the present embodiment is not limited tothe example illustrated in FIG. 3, and for example, at least a portionof each function of the control unit 10-1 or the interpersonal knowledgeDB 18 may be located on a cloud. In that case, the mobile body 1 a may,for example, transmit a captured image to the cloud and receive anemotion estimation result.

Further, the mobile body 1 a may include various motion sensors such asan acceleration sensor, a geomagnetic sensor, a gyro sensor, and thelike, detect information on motion of the mobile body 1 a, and use thedetected information in movement control of the moving unit 13.

(2-1-2. Operation)

FIG. 4 is a flowchart illustrating a movement control process accordingto the first embodiment. As illustrated in FIG. 4, first, the controlunit 10-1 of the mobile body 1 a measures a distance between the mobilebody 1 a and the communication target person (the target person 2) withthe distance and angle measuring unit 12 (step S103), measures aninterpersonal angle of the mobile body 1 a with respect to the targetperson 2 with the distance and angle measuring unit 12 (step S106), andestimates an emotion of the target person 2 with the emotion estimatingunit 10 a (step S109). Steps S103 to S109 may be performed atsubstantially the same time.

Next, the movement position calculating unit 10 b of the mobile body 1 acalculates a movement position with reference to the interpersonalposition knowledge DB 18 on the basis of the estimated emotion (stepS112).

Then, the movement control unit 10 c calculates a moving direction and amoving distance to the calculated movement position on the basis of thecurrent interpersonal distance and interpersonal angle with the targetperson 2 (step S115).

Then, the movement control unit 10 c executes a movement control commandto move to the movement position with respect to the moving unit 13(step S118). Specifically, the movement control unit 10 c outputs themoving direction and moving distance to the calculated movement positionto the moving unit 13 and executes a movement command. In this way, themobile body 1 a may move to an appropriate distance and angle inaccordance with the emotion of the target person 2 and performcommunication with the target person 2 without causing the target person2 psychological stress.

Then, Steps S103 to S118 are repeated until a predetermined endcondition (for example, reception of an end command by voice or gesture,a time limit, an end instruction, etc.) is satisfied (step S121).

An example of a movement control process according to the presentembodiment has been described above. However, the present embodiment isnot limited thereto, and for example, in the case of a configuration inwhich the emotion estimating unit 10 a of the mobile body 1 a is in apredetermined server on a cloud (cloud type mobile body control system),an operation process illustrated in FIG. 5 may be performed.

FIG. 5 is a sequence diagram illustrating another movement controlprocess according to the first embodiment. As illustrated in FIG. 5,first, the distance and angle measuring unit 12 of the mobile body 1 ameasures a distance between the mobile body 1 a and the target person 2(step S133). Further, the distance and angle measuring unit 12 measuresan interpersonal angle of the mobile body 1 a with respect to the targetperson 2 (step S136). Steps S133 and S136 may be performed atsubstantially the same time.

Then, the mobile body 1 a requests emotion estimation processing of thetarget person 2 from a server on a cloud (step S139). Here, the mobilebody 1 a transmits data, such as the captured image or collected voiceof the target person 2, used in the emotion estimation processing to theserver.

Next, the server analyzes the captured image or collected voice of thetarget person 2 in response to the request from the mobile body 1 a andestimates an emotion of the target person 2 (step S142). Then, theserver transmits a result of the estimation to the mobile body 1 a (stepS145).

Then, the movement position calculating unit 10 b of the mobile body 1 acalculates a movement position with reference to the interpersonalposition knowledge DB 18 on the basis of the emotion of the targetperson 2 estimated by the server and the current interpersonal distanceand interpersonal angle (step S148).

Then, the movement control unit 10 c calculates a moving direction and amoving distance to the calculated movement position on the basis of thecurrent interpersonal distance and interpersonal angle with the targetperson 2 (step S151).

Then, with respect to the moving unit 13, the movement control unit 10 cexecutes a movement control command to move to the movement position(step S154). Specifically, the movement control unit 10 c outputs themoving direction and moving distance to the calculated movement positionto the moving unit 13 and executes a movement command. In this way, themobile body 1 a may move to an appropriate distance and angle inaccordance with the emotion of the target person 2 and performcommunication with the target person 2 without causing the target person2 psychological stress.

The above-described process from steps S133 to S154 is repeated until apredetermined end condition (for example, reception of an end command byvoice or gesture, a time limit, an end instruction, etc.) is satisfied.

(2-1-3. Example of Controlling Movement)

With respect to appropriate movement control of the mobile body 1 acorresponding to an emotion of the target person 2 according to thepresent embodiment described above, a plurality of detailed examples ofcontrolling movement will be described below.

EXAMPLE 1 Movement to Initial Position

FIG. 6 is a view for describing an example of controlling movement ofthe mobile body 1 a at the start of communication according to the firstembodiment. As illustrated in FIG. 6, first, at the start ofcommunication, the mobile body 1 a moves from face-to-face with adefault interpersonal angle Ang.1 (for example, about 10°) with respectto a position 31 of the target person 2 to an initial position 32 of aninterpersonal distance D1 (the remote phase of the individual distance:for example, about 1 m). The default interpersonal angle and theinterpersonal distance may be stored in the interpersonal positionknowledge DB 18. Also, when moving to the initial position, the mobilebody 1 a may adjust an interpersonal angle and an interpersonal distancewithin a predetermined range in accordance with an emotion (positive ornegative) of the target person 2.

EXAMPLE 2-1 In Case in which Target Person has Positive Emotion

Next, control to a subsequent movement position of the mobile body 1 abased on an emotion of the target person 2 when the mobile body 1 a ismoved to the initial position 32 will be described with reference toFIG. 7. FIG. 7 is a view for describing movement control of the mobilebody 1 a in a case in which the target person 2 has a positive emotionaccording to the first embodiment.

In a case in which the emotion of the target person 2 is a positiveemotion (for example, the target person 2 is smiling) when the mobilebody 1 a is moved to the initial position 32 at the start ofcommunication, as illustrated in the upper part of FIG. 7, the mobilebody 1 a moves to a first proximate position 33 closer to the targetperson 2 than the initial position 32 with an interpersonal distance D2(the proximate phase of the individual distance: for example, about 50cm) as the limit. Here, by maintaining the appropriate interpersonalangle Ang.1 with the target person 2, the mobile body 1 a approaches thetarget person 2 without causing them stress.

Then, in a case in which the emotion of the target person 2 is apositive emotion (for example, the target person 2 is smiling) when themobile body 1 a is moved to the first proximate position 33, asillustrated in the lower part of FIG. 7, the mobile body 1 a moves to asecond proximate position 34, that is closer to the target person 2 thanthe first proximate position 33 and becomes side-by-side with the targetperson 2 by changing an angle, with an interpersonal distance D3 (theremote phase of the close distance: for example, about 30 cm) as alimit. When the mobile body 1 a is arranged side-by-side with the targetperson 2, the angle of the mobile body 1 a becomes an interpersonalangle Ang.2 close to about 90° with respect to the forward vector(forward direction) of the target person 2. In this way, the mobile body1 a is side-by-side with the target person 2 and faces substantially thesame direction as the target person 2, thereby increasing familiarity.

EXAMPLE 2-2 Movement Stop Control

Further, for example, the mobile body 1 a may continuously estimate anemotion of the target person 2 when moving from the initial position tothe first proximate position 33 without changing an angle as illustratedin the upper part of FIG. 7, and may stop moving when the emotion of thetarget person 2 changes from smiling to a normal state as illustrated inFIG. 8. In the example illustrated in FIG. 8, because the target person2 is no longer smiling and is in the normal state at the point at whichthe mobile body 1 a is moved to a position 35 of an interpersonaldistance D4 (D4>D2) from the target person 2, the mobile body 1 a stopsmoving in order to avoid causing the target person 2 psychologicalstress.

The mobile body 1 a may also perform movement stop control in accordancewith a predetermined interaction (that is, behavior) of the targetperson 2 when approaching the target person 2. FIG. 9 is a view fordescribing another type of movement stop control of the mobile bodyaccording to the present embodiment. As illustrated in the upper part ofFIG. 9, for example, in a case in which the target person 2 backs awayfrom the mobile body 1 a when the mobile body 1 a approaches the targetperson 2, the mobile body 1 a stops moving so as not to narrow theinterpersonal distance. Also, as illustrated in the lower part of FIG.9, for example, in a case in which the target person 2 looks away(diverts his or her gaze) when the mobile body 1 a approaches the targetperson 2 while face-to-face with the target person 2, the mobile body 1a stops moving so as not to narrow the interpersonal distance. Becausethe interactions, “backing away” and “looking away,” of the targetperson 2 described with reference to FIG. 9 are both behaviorsindicating that the target person 2 may have a negative emotion, themobile body 1 a stops moving so as not to cause the target person 2psychological stress.

EXAMPLE 2-3 When Target Person has Negative Emotion)

Next, movement control of the mobile body 1 a in a case in which thetarget person 2 has a negative emotion when the mobile body 1 a is movedto the first proximate position 33 or the second proximate position 34(see FIG. 7) will be described with reference to FIGS. 10 and 11. FIGS.10 and 11 are views for describing movement control of the mobile body 1a in a case in which the target person 2 has a negative emotionaccording to the first embodiment.

For example, in a case in which the emotion of the target person 2 is anegative emotion (for example, an angry face) when the mobile body 1 ais moved from the initial position 32 to the first proximate position 33(see the upper part of FIG. 7), as illustrated in FIG. 10, the mobilebody 1 a backs away from the target person 2 and moves to a first remoteposition 36 with an interpersonal distance D5 (the remote phase: forexample, about 1 m) as a limit. Here, the mobile body 1 a moves backwardwhile maintaining the appropriate interpersonal angle Ang.1 with thetarget person 2. In this way, the mobile body 1 a can avoid being tooclose to the target person 2 and causing the target person 2 stress.

Further, in a case in which the emotion of the target person 2 is anegative emotion (for example, an angry face) when the mobile body 1 ais moved from the first proximate position 33 to the second proximateposition 34 and is side-by-side with the target person 2 (see the lowerpart of FIG. 7), as illustrated in FIG. 11, the mobile body 1 a backsaway from the target person 2 and moves to a second remote position 37with an interpersonal distance D6 (the remote phase: for example, about1 m) as a limit. Here, although the mobile body 1 a has assumed theangle Ang.2 (see the lower part of FIG. 7) for increasing familiaritywith the target person 2 at the second proximate position 34, the mobilebody 1 a changes the direction to a direction substantially facing thetarget person 2 and moves backward while maintaining the appropriateangle Ang.1 so as not to cause the target person 2 stress. In this way,the mobile body 1 a can avoid being too close to the target person 2 andcausing the target person 2 stress.

EXAMPLE 3 In Case of Mobile Body that is Vertically Movable)

When the mobile body 1 a has a propeller and the like and can fly,because the mobile body 1 a can move in a vertical direction, the mobilebody 1 a can increase familiarity with the target person 2 or avoidcausing the target person 2 stress by adjusting the height of the mobilebody 1 a in accordance with a gaze of the target person 2. Hereinafter,this will be described in detail with reference to FIG. 12.

FIG. 12 is a view for describing vertical movement control of a mobilebody 1 x according to modified example of the first embodiment. Themobile body 1 x is realized using, for example, a robot that includes apropeller and the like and can fly. Generally, because being at a higherposition than a gaze of a partner gives a sense of intimidation to thepartner, as illustrated on the left in FIG. 12, the mobile body 1 xmoves to a position that is slightly lower than a gaze of a partner andis in the vicinity of the partner as an initial position. Here, theinterpersonal distance and the interpersonal angle (xz position) are theappropriate interpersonal distance D1 and interpersonal angle Ang.1 asin the case illustrated in FIG. 6.

Then, in a case in which the emotion of the target person 2 is positive(for example, a smile) when the mobile body 1 x is at the initialposition, the mobile body 1 x moves upward and reaches a height equal tothat of the gaze of the target person 2 as illustrated in the upperright part of FIG. 12, thereby increasing familiarity with the targetperson 2.

In a case in which the emotion of the target person 2 is negative (forexample, angry face) when the mobile body 1 x is at the initialposition, the mobile body 1 x moves downward and becomes lower than thegaze of the target person 2 as illustrated in the lower right part ofFIG. 12, thereby reducing stress to the target person 2.

The above-described vertical movement control in the height direction ofthe mobile body 1 x is not limited to the case of the initial positionand may also be similarly performed in accordance with an emotion of thetarget person 2 when the mobile body 1 x is at the first and secondproximate positions or the first and second remote positions. Forexample, the mobile body 1 x is side-by-side with the height that isequal to the height of the eye of the target person 2 when at the secondproximate position 34 (see the lower part of FIG. 7) and is at aposition diagonally lower than the height of the eye of the targetperson 2 when at the first remote position 36 (see FIG. 10).

EXAMPLE 4 Responding by Changing Direction of Mobile Body 1 a)

Although control in which only the interpersonal distance of the mobilebody 1 a or the interpersonal distance and the interpersonal angle arechanged in accordance with an emotion of the target person 2 has beendescribed in the above-described movement control examples, the presentembodiment is not limited thereto, and for example, only theinterpersonal angle of the mobile body 1 a may be changed. Hereinafter,an example will be described with reference to FIGS. 13 and 14.

FIG. 13 is a view for describing change of an interpersonal angle of themobile body 1 a in the case in which the target person 2 has a positiveemotion according to the first embodiment. For example, in a case inwhich the target person 2 smiles when the mobile body 1 a isface-to-face with the target person 2 at an interpersonal angle Ang.3 asillustrated in the upper part of FIG. 13, the mobile body 1 a changes adirection to reduce the absolute value of the interpersonal angle, forexample, faces the target person 2 at an interpersonal angle Ang.4(Ang.4<Ang.3), thereby further increasing familiarity with the targetperson 2.

In a case in which the target person 2 smiles when the mobile body 1 ais side-by-side with the target person 2 at an interpersonal angle Ang.5as illustrated in the lower part of FIG. 13, the mobile body 1 a changesthe direction to reduce the absolute value of the interpersonal angle,for example, faces the direction of the target person 2 at aninterpersonal angle Ang.6 (Ang.6<Ang.5), thereby further increasingfamiliarity with the target person 2.

FIG. 14 is a view for describing change of an interpersonal angle of themobile body 1 a in the case in which the target person 2 has a negativeemotion according to the first embodiment. For example, in a case inwhich the target person 2 has an angry face when the mobile body 1 a isface-to-face with the target person 2 at the interpersonal angle Ang.3as illustrated in the upper part of FIG. 14, the mobile body 1 a changesa direction to increase the absolute value of the interpersonal angle,for example, faces the target person 2 at an interpersonal angle Ang.7(Ang.7>Ang.3), thereby not causing the target person 2 psychologicalstress.

In a case in which the target person 2 has an angry face when the mobilebody 1 a is side-by-side with the target person 2 at the interpersonalangle Ang.5 as illustrated in the lower part of FIG. 14, the mobile body1 a changes the direction to increase the absolute value of theinterpersonal angle, for example, diverts its gaze from the targetperson 2 to an interpersonal angle Ang.8 (Ang.8>Ang.5), thereby notcausing the target person 2 psychological stress.

<2-2. Second Embodiment>

Next, a mobile body control system according to a second embodiment ofthe present disclosure will be described with reference to FIGS. 15 to20. In the second embodiment, a mobile body 1 b moves to a moreappropriate position using history information when communicating in thepast with the communication target person 2, thereby communicating withthe target person 2 without causing the target person 2 unnecessarystress.

(2-2-1. Configuration)

FIG. 15 is a block diagram illustrating an example of a configuration ofthe mobile body 1 b according to the second embodiment. As illustratedin FIG. 15, the mobile body 1 b according to the present embodimentincludes a control unit 10-2, the communication unit 11, the distanceand angle measuring unit 12, the moving unit 13, the camera 14, themicrophone 15, the speaker 16, the position measuring unit 17, theinterpersonal position knowledge DB 18, an individual information DB 19,and a communication history storage unit 20.

The control unit 10-2 is configured by a microcomputer having a CPU, aROM, a RAM, and a nonvolatile memory and controls each configuration ofthe mobile body 1 b. Further, as illustrated in FIG. 15, the controlunit 10-2 functions as the emotion estimating unit 10 a, the movementposition calculating unit 10 b, the movement control unit 10 c, and anindividual identifying unit 10 d.

The individual identifying unit 10 d performs individual identificationof the communication partner (the target person 2 in the presentembodiment). For example, the individual identifying unit 10 d acquiresan individual ID of the target person 2 with reference to the individualinformation DB 19 on the basis of a facial recognition result of acaptured image of the target person 2 captured by the camera 14. Here,parameters, such as facial feature amounts or voice feature amounts ofthe communication partner, used for individual identification andinformation on individuals (for example, an individual ID, name, age,sex, hobby and preference, etc.) are stored in the individualinformation DB 19.

The movement position calculating unit 10 b calculates an appropriatemovement position on the basis of the current emotion of the targetperson 2 estimated by the emotion estimating unit 10 a and acommunication history of the target person 2 acquired from thecommunication history storage unit 20 in accordance with the individualID of the target person 2 identified by the individual identifying unit10 d. Here, a data structure stored in the communication history storageunit 20 includes a time stamp, a target 1 (the target Ta illustrated inFIG. 2), a target 2 (the target Tb illustrated in FIG. 2), a distance(distance between the target 1 and the target 2: Xab), an angle 1 (Ang.aillustrated in FIG. 2), an angle 2 (Ang.b illustrated in FIG. 2), anemotion 1 (emotion of the target Ta), and an emotion 2 (emotion of thetarget Tb). For example, the time stamp is expressed as a UNIX(registered trademark) time, the target is expressed as a hexadecimalID, the distance is expressed as centimeters, the angle is expressed asdegrees, and the emotion is expressed as a value of valence and arousalnormalized to “−1 to 1.” An example of data in the communication historystorage unit 20 is shown in Table 1 below.

TABLE 1 Timestamp Target 1 Target 2 Distance Angle 1 Angle 2 Emotion 1Emotion 2 1421879415 C717EB3C 4E14D94C 128.6 23.7 7.6 0.7, 0.2 −0.4, 0.1. . . . . . . . . . . . . . . . . . . . . . . . 1421877811 065B61078E6A8451 201.4 87.4 −92.5 0.3, 0.4 −0.1, −0.3 . . . . . . . . . . . . .. . . . . . . . . . .

In the present embodiment, more specifically, a time stamp, an ID of thetarget person 2, an ID of the mobile body 1 b, a distance (aninterpersonal distance between the target person 2 and the mobile body 1b), and an angle (an interpersonal angle between the target person 2 andthe mobile body 1 b) are stored in the communication history storageunit 20. The movement position calculating unit 10 b acquires matchingdata or average value data of a plurality of matching data from thecommunication history storage unit 20 on the basis of the individual IDof the target person 2 and the individual ID of the mobile body 1 b anduses the acquired data in calculating the movement position.

When history information of the target person 2 is not obtained from thecommunication history storage unit 20, the movement position calculatingunit 10 b may also calculate an appropriate position and aninterpersonal angle corresponding to the current interpersonal distanceand interpersonal angle with the target person 2 and emotion of thetarget person 2 with reference to the interpersonal position knowledgeDB 18.

The configuration of the mobile body 1 b according to the presentembodiment has been described above in detail. Here, description of thesame configuration as the mobile body 1 a according to the firstembodiment described with reference to FIG. 3 will be omitted. Theconfiguration of the mobile body 1 b according to the second embodimentis not limited to the configuration illustrated in FIG. 15, and forexample, at least one of the emotion estimating unit 10 a, theindividual identifying unit 10 d, the individual information DB 19, andthe communication history storage unit 20 may be present on a cloud.

(2-2-2. Operation)

Next, an operation process of the mobile body control system accordingto the second embodiment will be described with reference to FIG. 16.FIG. 16 is a flowchart illustrating a movement control process accordingto the second embodiment. As illustrated in FIG. 16, first, the controlunit 10-2 of the mobile body 1 b performs individual identification ofthe communication target (the target person 2) by the individualidentifying unit 10 d (step S203). Also, the control unit 10-2 measuresan interpersonal distance with the target person 2 by the distance andangle measuring unit 12 (step S206), measures an interpersonal angle(step S209), and estimates emotion of the target person 2 by the emotionestimating unit 10 a (step S212). Steps S203 to S212 may be performedsubstantially at the same time.

Then, the movement position calculating unit 10 b of the mobile body 1 bacquires a communication history between the target person 2 and themobile body 1 b from the communication history storage unit 20 on thebasis of the identified individual ID of the target person 2 (stepS215).

Then, the movement position calculating unit 10 b calculates a movementposition on the basis of the acquired communication history (step S218).For example, at the start of communication, the movement positioncalculating unit 10 b calculates an initial position on the basis of theacquired communication history with the target person 2. In a case inwhich emotion of the target person 2 is positive when the mobile body 1b is at the initial position, the movement position calculating unit 10b determines whether the mobile body 1 b further approaches the targetperson 2 on the basis of the communication history with the targetperson 2. For example, in a case in which emotion of the target person 2when the mobile body 1 b was closer to the target person 2 than thecurrent interpersonal distance was positive based on the communicationhistory of the past, the movement position calculating unit 10 bcalculates a position closer to the target person 2 than the currentposition as the movement position.

Then, on the basis of the current interpersonal distance andinterpersonal angle with the target person 2, the movement control unit10 c calculates a moving direction and a moving distance to the movementposition calculated by the movement position calculating unit 10 b instep S218 (step S221).

Then, with respect to the moving unit 13, the movement control unit 10 cexecutes a movement control command to move to the movement position(step S224).

Then, the control unit 10-2 controls an interpersonal distance, aninterpersonal angle, and emotion of the target person 2 after themovement to be stored in the communication history storage unit 20 as acommunication history together with a time stamp (step S227).

Then, steps S203 to S227 are repeated until a predetermined endcondition (for example, reception of an end command by voice or gesture,time limit, end instruction, etc.) is satisfied (step S230).

An example of a movement control process according to the presentembodiment has been described above. However, the present embodiment isnot limited thereto, and for example, in a case of a configuration inwhich each of the emotion estimating unit 10 a, the individualidentifying unit 10 d, and the interpersonal position knowledge DB 18 ofthe mobile body 1 b is present in a predetermined server on a cloud(cloud type mobile body control system), an operation processillustrated in FIG. 17 may be performed.

FIG. 17 is a sequence diagram illustrating another movement controlprocess according to the second embodiment. As illustrated in FIG. 17,first, the control unit 10-2 of the mobile body 1 b requests anindividual identification server on a cloud for individualidentification (step S243). Here, the mobile body 1 b transmits data,such as the captured image or collected voice of the target person 2,used in the individual identification processing to the individualidentification server.

Next, the individual identification server analyzes the captured imageor collected voice of the target person 2 in response to the requestfrom the mobile body 1 b and performs individual identification (stepS246). Then, the individual identification server transmits a result ofthe identification to the mobile body 1 b (step S249).

Then, by the distance and angle measuring unit 12, the mobile body 1 bmeasures an interpersonal distance between the mobile body 1 b and thetarget person 2 (step S252) and measures the interpersonal angle (stepS255). Steps S252 and S255 may be performed substantially at the sametime.

Then, the mobile body 1 b requests an emotion estimation server on thecloud for emotion estimation processing of the target person 2 (stepS258). Here, the mobile body 1 b transmits data, such as the capturedimage or collected voice of the target person 2, used in the emotionestimation processing to the server.

Next, the emotion estimation server analyzes the captured image orcollected voice of the target person 2 in response to the request fromthe mobile body 1 b and estimates emotion of the target person 2 (stepS261). Then, the emotion estimation server transmits a result of theestimation to the mobile body 1 b (step S264).

Then, the movement position calculating unit 10 b of the mobile body 1 bacquires the communication history between the target person 2 and themobile body 1 b from the communication history storage unit 20 on thebasis of the individual ID of the target person 2 identified by theindividual identification server (step S267).

Then, in a case in which the communication history of the target person2 cannot be acquired (step S270/No), the mobile body 1 b requests aninterpersonal position knowledge DB server on the cloud forinterpersonal position knowledge data (step S273).

Then, the interpersonal position knowledge DB server searches for theinterpersonal position knowledge data in response to the request fromthe mobile body 1 b (step S276) and transmits a result of the searchingto the mobile body 1 b (step S279).

Then, the movement position calculating unit 10 b of the mobile body 1 bcalculates a movement position with reference to the acquiredcommunication history or interpersonal position knowledge data on thebasis of the estimated emotion of the target person 2 and the currentinterpersonal distance and interpersonal angle (step S282).

Then, the movement control unit 10 c of the mobile body 1 b calculates amoving direction and a moving distance to the calculated movementposition on the basis of the current interpersonal distance andinterpersonal angle with the target person 2 (step S285).

Then, with respect to the moving unit 13, the movement control unit 10 cexecutes a movement control command to move to the movement position(step S288). In this way, when the communication history of the targetperson 2 can be obtained, the mobile body 1 b can move to an appropriatedistance and angle on the basis of the past communication with thetarget person 2 and can communicate with the target person 2 withoutcausing the target person 2 psychological stress.

Then, the control unit 10-2 controls an interpersonal distance, aninterpersonal angle, and emotion of the target person 2 to be stored inthe communication history storage unit 20 as a communication historytogether with a time stamp (step S291).

The above-described process from steps S243 to S288 is repeated until apredetermined end condition (for example, reception of an end command byvoice or gesture, time limit, end instruction, etc.) is satisfied.

(2-2-3. Example of Controlling Movement)

With respect to appropriate movement control of the mobile body 1 bbased on a communication history of the target person 2 according to thesecond embodiment described above, a plurality of detailed examples ofcontrolling movement will be described below.

EXAMPLE 1 Movement to Initial Position

FIG. 18 is a view for describing an example of controlling movement ofthe mobile body 1 b at the start of communication according to thesecond embodiment. At the start of communication, the mobile body 1 acalculates an appropriate initial position at which there is no stressto the partner on the basis of the communication history of the targetperson 2 and moves.

For example, when the mobile body 1 b had a good relationship with thetarget person 2 (for example, a smiling face, positive emotion) in thepast and takes a close distance to the target person 2 or isside-by-side with the target person 2, as illustrated in the upper partof FIG. 18, the mobile body 1 b moves to an initial position 38 havingthe appropriate interpersonal angle Ang.1 with an interpersonal distanceD7 (the proximate phase: for example, about 50 cm) close to the targetperson 2 as a limit. In this way, when the past communication historywas good, the mobile body 1 b moves from the beginning to a place closeto the target person 2.

On the other hand, when the mobile body 1 b had a bad relationship withthe target person 2 (for example, angry face, negative emotion) in thepast and takes a far distance from the target person 2, as illustratedin the lower part of FIG. 18, the mobile body 1 b moves to an initialposition 39 having the appropriate interpersonal angle Ang.1 with aninterpersonal distance D5 (the remote phase: for example, about 1 m) farfrom the target person 2 as a limit. In this way, when the pastcommunication history was bad, the mobile body 1 b moves to a place farfrom the target person 2 at the start of communication.

EXAMPLE 2 Movement Control to Proximate Position

Next, in a case in which the target person 2 smiles (that is, has apositive emotion) when the mobile body 1 b is at a movement position(for example, the initial position), the mobile body 1 b performsmovement control to a proximate position that is closer to the targetperson 2 than the current position. Here, in the present embodiment,past emotion of the target person 2 when the mobile body 1 b moved to acloser distance to the target person 2 than the current interpersonaldistance is acquired from the communication history storage unit 20, andwhether to move to the proximate position is determined on the basis ofthe past situation. Hereinafter, this will be described in detail withreference to FIG. 19.

For example, as illustrated in the upper part of FIG. 19, in a case inwhich the mobile body 1 b had a good relationship with the partner whenapproaching the partner in the past (that is, the partner had positiveemotion even when the mobile body 1 b was approaching), the mobile body1 b controls to move from a current position 40 having an interpersonaldistance D7 to a proximate position 41 having an interpersonal distanceD8 (the proximate phase: for example, about 50 cm). Here, theinterpersonal angle takes the predetermined appropriate angle Ang.1stored in the interpersonal position knowledge DB 18 or the angle, atwhich the relation with the partner is good, calculated on the basis ofthe communication history.

As illustrated in the lower part of FIG. 19, in a case in which themobile body 1 b had a bad relationship with the partner when approachingthe partner in the past (that is, the partner had negative emotion whenthe mobile body 1 b was approaching), that mobile body 1 b controls soas not to approach the target person 2 and stop at the current position40 having the interpersonal distance D7 even when the target person 2currently smiles (that is, has a positive emotion). Here, theinterpersonal angle takes the predetermined appropriate angle Ang.1stored in the interpersonal position knowledge DB 18 or the angle, atwhich the relation with the partner is good, calculated on the basis ofthe communication history.

As described above, when it is estimated that the current emotion of thetarget person 2 is positive emotion, by referring to the pastcommunication history with the target person 2, the mobile body 1 b canappropriately determine whether to further approach the target person 2and more reliably avoid causing the target person 2 stress.

EXAMPLE 3 Movement Control to Side-by-side Position

Then, in a case in which the target person 2 smiles (that is, has apositive emotion) when the mobile body 1 b is at a movement position(for example, the proximate position), the mobile body 1 b performsmovement control to a close position that is closer to the target person2 than the current position and is side-by-side with the target person2. Here, in the present embodiment, past emotion of the target person 2when the mobile body 1 b was at a closer distance (for example, a closeposition) from the target person 2 than the current interpersonaldistance is acquired from the communication history storage unit 20, andwhether to move to the proximate position is determined on the basis ofthe past situation. Hereinafter, this will be described in detail withreference to FIG. 20.

For example, as illustrated in the upper part of FIG. 20, in a case inwhich the mobile body 1 b had a good relationship with the partner whenthe mobile body 1 b approached the partner and became side-by-side withthe partner in the past (that is, the partner had positive emotion), themobile body 1 b controls to move from a current position 42 to a closeposition 43 having an interpersonal angle D9 (the close distance: forexample, about 30 cm). Here, the interpersonal angle takes thepredetermined appropriate side-by-side angle Ang.2 stored in theinterpersonal position knowledge DB 18 or the side-by-side angle, atwhich the relation with the partner is good, calculated on the basis ofthe communication history.

As illustrated in the lower part of FIG. 20, in a case in which themobile body 1 b had a bad relationship with the partner when the mobilebody 1 b approached the partner and became side-by-side with the partnerin the past (that is, the partner had negative emotion), that mobilebody 1 b controls so as not to approach the target person 2 and becomeside-by-side with the target person 2 and stops at the current position42 having an interpersonal distance D10 (the proximate phase: forexample, about 50 cm) even when the target person 2 currently smiles(that is, has a positive emotion). Here, the interpersonal angle takesthe predetermined appropriate angle Ang.1 stored in the interpersonalposition knowledge DB 18 or the angle, at which the relation with thepartner is good, calculated on the basis of the communication history.

As described above, when it is estimated that the current emotion of thetarget person 2 is positive emotion, by referring to the pastcommunication history with the target person 2, the mobile body 1 b canappropriately determine whether to further approach the target person 2and become side-by-side with the target person 2, and more reliablyavoid causing the target person 2 stress.

<2-3. Third Embodiment>

Next, a mobile body control system according to a third embodiment ofthe present disclosure will be described with reference to FIGS. 21 to29. In the present embodiment, a mobile body 1 c moves to a moreappropriate position by estimating surrounding atmosphere based onemotion of a person who is present around the target person 2, inaddition to emotion of the target person 2, thereby communicating withthe target person 2 without causing the target person 2 or thesurrounding person stress.

(2-3-1. Configuration)

FIG. 21 is a block diagram illustrating an example of a configuration ofthe mobile body 1 c according to the third embodiment. As illustrated inFIG. 21, the mobile body 1 c according to the present embodimentincludes a control unit 10-3, the communication unit 11, the distanceand angle measuring unit 12, the moving unit 13, the camera 14, themicrophone 15, the speaker 16, the position measuring unit 17, theinterpersonal position knowledge DB 18, the individual information DB19, and the communication history storage unit 20.

The control unit 10-3 is configured by a microcomputer having a CPU, aROM, a RAM, and a nonvolatile memory and controls each configuration ofthe mobile body 1 c. Further, as illustrated in FIG. 21, the controlunit 10-3 functions as the emotion estimating unit 10 a, the movementposition calculating unit 10 b, the movement control unit 10 c, theindividual identifying unit 10 d, and an atmosphere estimating unit 10e.

The atmosphere estimating unit 10 e has a function of estimatingsurrounding atmosphere of the target person 2. For example, theatmosphere estimating unit 10 e estimates surrounding atmosphere(atmosphere is good/bad) on the basis of emotion of a person who ispresent around the target person 2 that is estimated by the emotionestimating unit 10 a. Also, when estimating surrounding atmosphere onthe basis of emotion of a surrounding person, the atmosphere estimatingunit 10 e may more accurately estimate the surrounding atmosphere byreferring to a distance between the target person 2 and the surroundingperson.

More specifically, the atmosphere estimating unit 10 e may calculate thesum of emotions of people who are present around the target person 2 asthe surrounding atmosphere. When emotion of a person is expressed usingvalence and arousal, the surrounding atmosphere may be calculated usingEquation 1 below in which an influence due to a distance d (a distancebetween the target person 2 and a surrounding person or a distancebetween a plurality of surrounding people) is added to the normalizedvalence V and arousal A.

$\begin{matrix}{{V = {\sum\limits_{i = 0}^{n}\;\frac{v_{i}}{d_{i}^{2}}}}{A = {\sum\limits_{i = 0}^{n}\;\frac{a_{i}}{d_{i}^{2}}}}} & \left( {{Equation}\mspace{14mu} 1} \right)\end{matrix}$

The surrounding atmosphere may also be calculated by further adding aplace or situation (a public place, home, company, school, in a meeting,party, etc.).

The movement position calculating unit 10 b calculates an appropriatemovement position on the basis of emotion of the target person 2estimated by the emotion estimating unit 10 a and surrounding atmosphereof the target person 2 estimated by the atmosphere estimating unit 10 e.When individual identification of the target person 2 is possible by theindividual identifying unit 10 d, the movement position calculating unit10 b may calculate an appropriate movement position on the basis of acommunication history between the target person 2 and the mobile body 1c acquired from the communication history storage unit 20, in additionto the current emotion and surrounding atmosphere of the target person2. The communication history storage unit 20 according to the presentembodiment has a data structure that further includes atmosphericinformation in addition to the time stamp, the target 1, the target 2,the distance, the angle 1, the angle 2, the emotion 1, and the emotion2.

The configuration of the mobile body 1 c according to the presentembodiment has been described above in detail. Here, description of thesame configurations as the mobile bodies 1 a and 1 b according to thefirst and second embodiments described with reference to FIG. 3 and FIG.15 will be omitted. The configuration of the mobile body 1 c accordingto the third embodiment is not limited to the configuration illustratedin FIG. 21, and for example, at least one of the emotion estimating unit10 a, the individual identifying unit 10 d, the atmosphere estimatingunit 10 e, the individual information DB 19, and the communicationhistory storage unit 20 may be present on a cloud.

(2-3-2. Operation)

Next, an operation process of the mobile body control system accordingto the third embodiment will be described with reference to FIG. 22.FIG. 22 is a flowchart illustrating a movement control process accordingto the third embodiment. As illustrated in FIG. 22, first, the controlunit 10-3 of the mobile body 1 c performs individual identification ofthe communication target (the target person 2) by the individualidentifying unit 10 d (step S303). Also, the control unit 10-3 measuresan interpersonal distance with the target person 2 by the distance andangle measuring unit 12 (step S306), measures an interpersonal angle(step S309), and estimates emotion of the target person 2 by the emotionestimating unit 10 a (step S312). Also, the control unit 10-3 estimatessurrounding atmosphere of the target person 2 by the atmosphereestimating unit 10 e (step S315). An atmosphere estimation process willbe described below with reference to FIG. 23. Steps S303 to S315 may beperformed substantially at the same time.

Then, the movement position calculating unit 10 b of the mobile body 1 cacquires a communication history between the target person 2 and themobile body 1 b from the communication history storage unit 20 on thebasis of the individual ID of the target person 2 when the target person2 can be identified (step S318).

Then, the movement position calculating unit 10 b calculates a movementposition on the basis of the estimated current atmosphere around thetarget person 2 (step S321). Here, the movement position calculatingunit 10 b calculates a movement position on the basis of movementcontrol data corresponding to pre-registered surrounding atmosphere byreferring to the interpersonal position knowledge DB 18. When thecommunication history can be obtained by step S318, the movementposition calculating unit 10 b may also calculate a movement positionwith reference to the communication history. For example, even in a casein which the target person 2 currently smiles and has positive emotion,when the surrounding atmosphere of the target person 2 is bad (whenmultiple people present around the target person 2 have negativeemotions), the movement position calculating unit 10 b calculates aposition receding from the target person 2 as a movement position ordoes not calculate a movement position so as not to move from thecurrent position with reference to the interpersonal position knowledgeDB 18. On the other hand, when the surrounding atmosphere of the targetperson 2 is good (when multiple people present around the target person2 have positive emotions) in the case in which the target person 2currently smiles and has positive emotion, the movement positioncalculating unit 10 b calculates a position closer to the target person2 than the current position as a movement position. In this way, themobile body 1 c according to the present embodiment can calculate amovement position corresponding to whether the atmosphere around thetarget person 2 is good or bad. By this, the mobile body 1 c can avoid abehavior of causing the target person 2 or a surrounding person stress,as, for example, when communicating with the target person 2 in thevicinity of or in close contact with the target person 2 in a situationin which the atmosphere is bad.

Then, on the basis of the current interpersonal distance andinterpersonal angle with the target person 2, the movement control unit10 c calculates a moving direction and a moving distance to the movementposition calculated by the movement position calculating unit 10 b instep S321 (step S324).

Then, with respect to the moving unit 13, the movement control unit 10 cexecutes a movement control command to move to the movement position(step S327).

Then, the control unit 10-3 controls an interpersonal distance, aninterpersonal angle, emotion of the target person 2, and information onsurrounding atmosphere after the movement to be stored in thecommunication history storage unit 20 as a communication historytogether with a time stamp (step S330).

Then, steps S303 to S330 are repeated until a predetermined endcondition (for example, reception of an end command by voice or gesture,time limit, end instruction, etc.) is satisfied (step S333).

An example of a movement control process according to the presentembodiment has been described above. Next, the atmosphere estimationprocess illustrated in step S315 will be described in detail withreference to FIG. 23.

FIG. 23 is a flowchart illustrating the atmosphere estimation processaccording to the present embodiment. As illustrated in FIG. 23, first,the mobile body 1 c acquires information on a person who is presentaround the target person 2 (step S343). Specifically, the mobile body 1c acquires a captured image, collected voice, distance measuringinformation, and the like of a person who is present around the targetperson 2 by various sensors (the distance and angle measuring unit 12,the camera 14, the microphone 15) provided in the mobile body 1 c.

Then, the distance and angle measuring unit 12 measures a distancebetween the target person 2 and the surrounding person (step S346). Forexample, the distance and angle measuring unit 12 may calculate thedistance between the target person 2 and the surrounding person usingtriangulation.

Then, the emotion estimating unit 10 a estimates emotion of thesurrounding person on the basis of the acquired captured image orcollected voice (step S349).

Then, the atmosphere estimating unit 10 e estimates the surroundingatmosphere on the basis of the estimated emotion of the surroundingperson and the distance between the surrounding person and the targetperson 2 and updates an atmospheric value (for example, a total value ofnegative/positive emotions) (step S352).

Then, steps S346 to S352 are repeated until analyses of all peoplearound the target person 2 are done (step S355).

As described above, in the present embodiment, a surrounding atmosphericvalue is calculated on the basis of emotion of a surrounding person ofthe target person 2 and a distance between the target person 2 and thesurrounding person (that is, atmosphere is estimated).

(2-2-3. Example of Controlling Movement)

Next, with respect to movement control of the mobile body 1 c inaccordance with surrounding atmosphere according to the thirdembodiment, a plurality of detailed examples of controlling movementwill be described below.

EXAMPLE 1 Example of Controlling Movement Using Interpersonal PositionKnowledge DB 18

The movement position calculating unit 10 b of the mobile body 1 c cancalculate a movement position with reference to the interpersonalposition knowledge DB 18 on the basis of estimated surroundingatmosphere. Hereinafter, movement control content stored in theinterpersonal position knowledge DB 18 will be described with referenceto FIGS. 24 to 26.

FIG. 24 is a view illustrating an example of controlling movement of themobile body 1 c in a case in which surrounding atmosphere is bad. Asillustrated in FIG. 24, even if the target person 2 smiles and haspositive emotion, when atmosphere of a surrounding place P1 based onemotions of people 3 a to 3 d around the target person 2 is estimated asbad, the mobile body 1 c controls so as not to approach the targetperson 2. For example, the mobile body 1 c maintains the remote phase ofthe individual distance (about 1 m) and takes the predetermined angleAng.1 that does not give stress to the partner as an interpersonalangle. The atmosphere of the surrounding place P1 can be calculated byadding an influence due to distances (distances M1 to M4) from thepeople 3 a to 3 d to the target person 2 to the emotions of thesurrounding people 3 a to 3 d. In the case in which the atmosphere ofthe surrounding place P1 is estimated as bad, it is assumed that, forexample, V is lower than a negative predetermined value in the sum ofemotions (valences) of the surrounding people.

FIG. 25 is a view illustrating an example of controlling movement of themobile body 1 c in a case in which surrounding atmosphere is good. Asillustrated in FIG. 25, when the target person 2 smiles and has positiveemotion, and atmosphere of a surrounding place P2 based on emotions ofpeople 3 a to 3 d around the target person 2 is estimated as good, themobile body 1 c controls so as not to approach the target person 2. Forexample, the mobile body 1 c approaches the target person 2 and forms afamiliar relationship with the target person 2. For example, the mobilebody 1 c maintains the proximate phase of the individual distance (about50 cm) and takes the predetermined angle Ang.1 that does not give stressto the partner as an interpersonal angle. When the target person 2smiles and the surrounding atmosphere is good even when the mobile body1 c is at about 50 cm from the target person 2, the mobile body 1 cfurther approaches the target person 2, approaches the target person 2and becomes side-by-side with the target person 2 with the remote phaseof the close distance (about 30 cm) as a limit, and performs familiarcommunication with the target person 2. The atmosphere of thesurrounding place P2 can be calculated by adding an influence due todistances (distances M1 to M4) from the people 3 a to 3 d to the targetperson 2 to the emotions of the surrounding people 3 a to 3 d. In thecase in which the atmosphere of the surrounding place P1 is estimated asgood, it is assumed that, for example, V is a positive first thresholdvalue or larger and less than a positive second threshold value in thesum of emotions (valences) of the surrounding people.

FIG. 26 is a view for describing an example of controlling movement ofthe mobile body 1 c in a case in which an atmosphere between the targetperson 2 and a person close to the target person 2 is extremely good. Asillustrated in FIG. 26, even if the target person 2 smiles and haspositive emotion, when atmosphere between the target person 2 and aperson 3 a close to the target person 2 is estimated as extremely goodatmosphere (that is, familiar atmosphere), the mobile body 1 c controlsso as not to approach the target person 2. For example, the mobile body1 c maintains the proximate phase of the individual distance (about 50cm) and takes the predetermined angle Ang.1 that does not give stress tothe partner as an interpersonal angle. In the extremely good atmosphere,it is assumed that, for example, V is the positive second thresholdvalue or larger in the sum of emotions (valences) of the surroundingpeople. As illustrated in FIG. 26, because a distance M5 between thetarget person 2 and the person 3 a close to the target person 2 issmall, the “total of emotions (valences) of the surrounding people”calculated by the square of the distance as shown in Equation 1 abovebecomes extremely large and is assumed to exceed the second thresholdvalue.

The above-described relationship between the atmosphere V of thesurrounding place and the interpersonal distance d between the mobilebody 1 c and the target person 2 is shown in the graph of FIG. 27. FIG.27 is a graph illustrating an example of the relationship between theatmosphere V of the surrounding place and the interpersonal distance dbetween the mobile body 1 c and the target person 2.

As illustrated in FIG. 27, when the atmosphere V of the place is lowerthan a negative predetermined value (here, the same as the firstthreshold value) (that is, the atmosphere is bad), the mobile body 1 ccontrols so as not to approach the target person 2. When the atmosphereV of the place is the positive first threshold value or larger and islower than the positive second threshold value (that is, the atmosphereis good), the mobile body 1 c controls to approach the target person 2and perform familiar communication with the target person 2. When theatmosphere V of the place is the positive second threshold value orlarger (that is, the atmosphere is extremely good and familiar), themobile body 1 c controls so as not to approach the target person 2.

In this way, in addition to emotion of the target person 2, by adjustingan interpersonal distance and an interpersonal angle with the targetperson 2 in accordance with atmosphere of a place, the mobile body 1 cmay not give stress to the partner or the surroundings.

EXAMPLE 2 Example of Controlling Movement Using Communication HistoryStorage Unit 20

Although movement control is performed in accordance with emotion of apartner or atmosphere of a place (the total value of emotions ofsurrounding people) in accordance with movement control contentpre-stored in the interpersonal position knowledge DB 18 in theabove-described example, the present embodiment is not limited thereto.For example, more appropriate movement control may be performed on thebasis of the communication history with the target person 2 stored inthe communication history storage unit 20. Hereinafter, this will bedescribed in detail with reference to FIGS. 28 and 29.

FIG. 28 is a view illustrating an example of movement control based on acommunication history according to the present embodiment. movementcontrol of the mobile body 1 c when the target person 2 smiles andatmosphere of a place P4 is good (surrounding people also have smiles ontheir faces and have positive emotions) will be described in FIG. 28.The mobile body 1 c inquires the communication history storage unit 20of emotion of the target person 2 or surrounding atmosphere when themobile body 1 c approaches closer to the target person 2 than thecurrent point in a situation in which the target person 2 smiles and thesurrounding atmosphere is also good. If emotion of the target person 2was positive when the mobile body 1 c approached the target person 2 inthe same situation in the past, as illustrated in the upper part of FIG.28, the mobile body 1 c controls movement to approach closer to thetarget person 2 than the current position. On the other hand, if emotionof the target person 2 was negative when the mobile body 1 c approachedthe target person 2 in the same situation in the past, as illustrated inthe lower part of FIG. 28, the mobile body 1 c may control so as not toapproach the target person 2 even when the target person 2 currentlysmiles and the surrounding atmosphere is good, thereby not causing thetarget person 2 stress.

FIG. 29 is a view illustrating an example of movement control based on acommunication history according to the present embodiment. movementcontrol of the mobile body 1 c when the target person 2 smiles andatmosphere of a place P5 is bad (surrounding people have angry faces andhave negative emotions) will be described in FIG. 29. The mobile body 1c inquires the communication history storage unit 20 of emotion of thetarget person 2 or surrounding atmosphere when the mobile body 1 capproaches closer to the target person 2 than the current point in asituation in which the target person 2 smiles and the surroundingatmosphere is bad. If emotion of the target person 2 was negative whenthe mobile body 1 c approached the target person 2 in the same situationin the past, as illustrated in the upper part of FIG. 29, the mobilebody 1 c controls so as not to approach the target person 2 more thanthe current position, thereby not causing the target person 2 stress. Onthe other hand, if emotion of the target person 2 was positive when themobile body 1 c approached the target person 2 in the same situation inthe past, as illustrated in the lower part of FIG. 29, the mobile body 1c may control movement to approach the target person 2 even when thesurrounding atmosphere is bad.

«3. Summary»

As described above, in a mobile body control system according to anembodiment of the present disclosure, the mobile body 1 moves to anappropriate interpersonal distance and interpersonal angle in accordancewith emotion of the target person 2, who is a communication target, sothat the mobile body 1 does not give psychological stress to the targetperson 2 and performs comfortable communication with the target person2.

When a communication history with the target person 2 is beingaccumulated, by referring to the communication history, the mobile body1 can move to a more appropriate position and can perform comfortablecommunication with the target person 2 without causing the target person2 psychological stress.

By taking into consideration atmosphere of a place based on emotion of asurrounding person of the target person 2, the mobile body 1 can move toa more appropriate position and can perform comfortable communicationwith the target person 2 without causing the target person 2 or thesurrounding person psychological stress.

The preferred embodiment(s) of the present disclosure has/have beendescribed above with reference to the accompanying drawings, whilst thepresent disclosure is not limited to the above examples. A personskilled in the art may find various alterations and modifications withinthe scope of the appended claims, and it should be understood that theywill naturally come under the technical scope of the present disclosure.

For example, it is also possible to create a computer program forcausing the function of the mobile body 1 to be exerted on hardware suchas a CPU, a ROM, a RAM, and the like incorporated in the mobile body 1described above. A computer-readable storage medium storing the computerprogram is also provided.

Further, the mobile body control system according to the presentembodiment may be a mobile body system in which at least a part of theconfiguration of the mobile body 1 is located on a cloud.

Further, the effects described in this specification are merelyillustrative or exemplified effects, and are not limitative. That is,with or in the place of the above effects, the technology according tothe present disclosure may achieve other effects that are clear to thoseskilled in the art from the description of this specification.

Additionally, the present technology may also be configured as below.

(1)

A mobile body control system including:

a moving unit configured to move;

a measuring unit configured to measure an angle and a distance with atarget which is a communication target;

an emotion estimating unit configured to estimate an emotion of thetarget; and

a control unit configured to control the moving unit to move a mobilebody to an initial position with an appropriate angle and distance withrespect to the target in accordance with the estimated emotion.

(2)

The mobile body control system according to (1), in which, when theemotion estimating unit estimates that the target has a positiveemotion, the control unit controls the moving unit to move the mobilebody to a first proximate position at which a distance to the target iscloser than at the initial position, without changing an angle withrespect to the target.

(3)

The mobile body control system according to (2), in which, when theemotion estimating unit estimates that the target has a positive emotionwhen the mobile body is at the first proximate position, the controlunit controls the moving unit to move the mobile body to a secondproximate position at which a distance to the target is closer than atthe first proximate position, while changing the angle with respect tothe target.

(4)

The mobile body control system according to (3), in which the controlunit controls the moving unit so that the mobile body changes from anangle at which the mobile body is face-to face with the target at thefirst proximate position to an angle at which the mobile body isside-by-side with the target at the second proximate position.

(5)

The mobile body control system according to (3) or (4), in which, whenthe emotion estimating unit estimates that the target has a negativeemotion when the mobile body is at the second proximate position, thecontrol unit controls the moving unit to move to the first proximateposition, while changing the angle with respect to the target.

(6)

The mobile body control system according to (2), in which, when theemotion estimating unit estimates that the target has a negative emotionwhen the mobile body is at the first proximate position, the controlunit controls the moving unit to move to the initial position, withoutchanging the angle with respect to the target.

(7)

The mobile body control system according to any one of (2) to (6), inwhich, when the emotion estimating unit estimates that the target has anegative emotion, the control unit controls the moving unit to change anangle of the mobile body with respect to the target.

(8)

The mobile body control system according to (7), in which the controlunit controls the moving unit to increase the angle of the mobile bodywith respect to the target.

(9)

The mobile body control system according to any one of (1) to (8),further including:

an identifying unit configured to perform individual identification ofthe target; and

a storage control unit configured to control an angle and a distancebetween the mobile body and the target measured by the measuring unitand an emotion of the target when the mobile body is located at theangle and the distance to be stored, for each identified individual, ashistory information in a storage unit,

in which the control unit controls the moving unit to move to anappropriate position with respect to the target on the basis of thehistory information on the angle and the distance with the target andthe emotion of the target stored in the storage unit.

(10)

The mobile body control system according to (9), in which, even when thetarget currently has a positive emotion, the control unit controlswhether to move to a third proximate position at which a distance to thetarget is closer than at the current position of the mobile body on thebasis of the history information.

(11)

The mobile body control system according to any one of (1) to (10),further including

an atmosphere estimating unit configured to estimate a surroundingatmosphere of the target,

in which the control unit controls the moving unit to move to anappropriate position with respect to the target on the basis of thesurrounding atmosphere.

(12)

The mobile body control system according to (11), in which theatmosphere estimating unit estimates the surrounding atmosphere of thetarget on the basis of an emotion of another target located around thetarget.

(13)

The mobile body control system according to (12), in which theatmosphere estimating unit estimates the surrounding atmosphere of thetarget on the basis of a distance between the other target locatedaround the target and the target or a distance between a plurality ofother targets, and the emotion of the other target.

(14)

The mobile body control system according to any one of (11) to (13), inwhich the control unit controls the mobile body to move to anappropriate position with respect to the target on the basis of thecurrent surrounding atmosphere and history information including anangle and a distance with the target, a surrounding atmosphere, and anemotion of the target in the past stored in a storage unit.

(15)

The mobile body control system according to any one of (1) to (14), inwhich the appropriate initial position has a preset distance and angle.

(16)

A control method including:

measuring, by a measuring unit, an angle and a distance with a targetwhich is a communication target;

estimating an emotion of the target; and

controlling a moving unit, by a control unit, to move a mobile body toan initial position with an appropriate angle and distance with respectto the target in accordance with the estimated emotion.

(17)

A storage medium having a program stored therein, the program causing acomputer to function as:

a moving unit configured to move;

a measuring unit configured to measure an angle and a distance with atarget which is a communication target;

an emotion estimating unit configured to estimate an emotion of thetarget; and

a control unit configured to control the moving unit to move a mobilebody to an initial position with an appropriate angle and distance withrespect to the target in accordance with the estimated emotion.

REFERENCE SIGNS LIST

-   1, 1 a, 1 b, 1 c mobile body-   10, 10-1 to 10-3 control unit-   10 a emotion estimating unit-   10 b movement position calculating unit-   10 c motion control unit-   10 d individual identifying unit-   10 e atmosphere estimating unit-   11 communication unit-   12 distance and angle measuring unit-   13 moving unit-   14 camera-   15 microphone-   16 speaker-   17 position measuring unit-   18 interpersonal position knowledge DB-   19 individual information DB-   20 communication history storage unit

The invention claimed is:
 1. A mobile body control system, comprising: amoving unit configured to move a mobile body; a measuring unitconfigured to measure an angle and a distance of the mobile body withrespect to a first target which is a communication target; an emotionestimating unit configured to estimate an emotion of the first target;and a control unit configured to: control the moving unit to move themobile body to an initial position having a first angle and a firstdistance with respect to the first target, wherein the first angle andthe first distance is based on the estimated emotion; and control themoving unit to move the mobile body to a first proximate position basedon an estimation, by the emotion estimating unit, that the emotion ofthe first target is a positive emotion, wherein the first proximateposition is at a second distance to the first target, the seconddistance is closer to the first target than the first distance, and themobile body is moved to the first proximate position without a change inthe first angle with respect to the first target.
 2. The mobile bodycontrol system according to claim 1, wherein, based on an estimation, bythe emotion estimating unit, that the emotion of the first target is thepositive emotion when the mobile body is at the first proximateposition, the control unit is further configured to control the movingunit to move the mobile body to a second proximate position, the secondproximate position is at a third distance to the first target, the thirddistance is closer to the first target than the second distance at thefirst proximate position, and the mobile body is moved to the secondproximate position with a change in the first angle with respect to thefirst target.
 3. The mobile body control system according to claim 2,wherein the control unit is further configured to control the movingunit to move the mobile body so that a second angle at which the mobilebody is face-to face with the first target at the first proximateposition is changed to a third angle at which the mobile body isside-by-side with the first target at the second proximate position. 4.The mobile body control system according to claim 3, wherein based on anestimation, by the emotion estimating unit, that the emotion of thefirst target is a negative emotion when the mobile body is at the secondproximate position, the control unit is further configured to controlthe moving unit to move the mobile body to the first proximate position,and the mobile body is moved to the first proximate position with achange in the third angle with respect to the first target.
 5. Themobile body control system according to claim 1, wherein, based on anestimation, by the emotion estimating unit, that the emotion of thefirst target is a negative emotion when the mobile body is at the firstproximate position, the control unit is further configured to controlthe moving unit to move the mobile body to the initial position, and themobile body is moved to the initial position without a change in thefirst angle with respect to the first target.
 6. The mobile body controlsystem according to claim 1, wherein, based on an estimation, by theemotion estimating unit, that the emotion of the first target is anegative emotion, the control unit is further configured to control themoving unit to move the mobile body to change the first angle of themobile body with respect to the first target.
 7. The mobile body controlsystem according to claim 6, wherein the control unit is furtherconfigured to control the moving unit to move the mobile body toincrease the first angle of the mobile body with respect to the firsttarget.
 8. The mobile body control system according to claim 1, furthercomprising: an identifying unit configured to identify the first target;and a storage control unit configured to store an angle and a distancebetween the mobile body and the first target measured by the measuringunit and an emotion of the first target when the mobile body is locatedat the angle and the distance, wherein the angle and the distancebetween the mobile body and the first target is stored in a storage unitas history information, wherein the control unit is further configuredto control the moving unit to move the mobile body with respect to thefirst target based on the history information stored in the storageunit.
 9. The mobile body control system according to claim 8, whereinbased on the positive emotion of the first target, the control unit isfurther configured to control the moving unit to move the mobile body toa third proximate position based on the stored history information, thethird proximate position is at a fourth distance to the first target,and the fourth distance is closer to the first target than at a currentposition of the mobile body.
 10. The mobile body control systemaccording to claim 1, further comprising: an atmosphere estimating unitconfigured to estimate a surrounding atmosphere of the first target,wherein the control unit is further configured to control the movingunit to move the mobile body with respect to the first target based onthe surrounding atmosphere.
 11. The mobile body control system accordingto claim 10, wherein the atmosphere estimating unit is furtherconfigured to estimate the surrounding atmosphere of the first targetbased on an emotion of a second target, and the second target is locatedaround the first target.
 12. The mobile body control system according toclaim 11, wherein the atmosphere estimating unit is further configuredto estimate the surrounding atmosphere of the first target based on adistance between the second target and the first target or a distancebetween a plurality of targets and the first target, and the emotion ofthe second target.
 13. The mobile body control system according to claim10, wherein the control unit is further configured to control the movingunit to move the mobile body with respect to the first target based onthe surrounding atmosphere and history information, and the historyinformation includes an angle and a distance with respect to the firsttarget, the surrounding atmosphere, and a past emotion of the firsttarget stored in a storage unit.
 14. The mobile body control systemaccording to claim 1, wherein the first distance at the initial positionis a determined distance and the first angle at the initial position isa determined angle.
 15. A control method, comprising: measuring, by ameasuring unit, an angle and a distance of a mobile body with respect toa target which is a communication target; estimating, by an emotionestimating unit, an emotion of the target; controlling a moving unit, bya control unit, to move the mobile body to an initial position having anangle and a first distance with respect to the target, wherein the angleand the first distance is based on the estimated emotion; andcontrolling the moving unit, by the control unit, to move the mobilebody to a proximate position based on an estimation that the emotion ofthe target is a positive emotion, wherein the proximate position is at asecond distance to the target, the second distance is closer to thetarget than the first distance, and the mobile body is moved to theproximate position without a change in the angle with respect to thetarget.
 16. A non-transitory computer-readable medium having storedthereon, computer-executable instructions which when executed by acomputer cause the computer to execute operations, the operationscomprising: measuring an angle and a distance of a mobile body with atarget which is a communication target; estimating an emotion of thetarget; controlling a moving unit to move the mobile body to an initialposition having an angle and a first distance with respect to thetarget, wherein the angle and the first distance is based on theestimated emotion; and controlling the moving unit to move the mobilebody to a proximate position based on an estimation that the emotion ofthe target is a positive emotion, wherein the proximate position is at asecond distance to the target, the second distance is closer to thetarget than the first distance, and the mobile body is moved to theproximate position without a change in the angle with respect to thetarget.
 17. A mobile body control system, comprising: a moving unitconfigured to move a mobile body; a measuring unit configured to measurean angle and a distance of the mobile body with respect to a targetwhich is a communication target; an emotion estimating unit configuredto estimate an emotion of the target; and a control unit configured to:control the moving unit to move the mobile body to an initial positionhaving an angle and a first distance with respect to the target, whereinthe angle and the first distance is based on the estimated emotion; andcontrol the moving unit to move the mobile body to change the angle ofthe mobile body with respect to the target based on an estimation, bythe emotion estimating unit, that the emotion of the target is anegative emotion.